1. Technical Field
The present invention relates to paper handling devices for feeding copy paper through photocopying machines and like devices, and more particularly, the present invention relates to a continuous feed photocopying apparatus with improvements in paper supply, feed path, and the related guide mechanisms for such photocopying machines.
2. Background Art
There are numerous copying devices in commercial use which use a xerographic process or like dry method of high speed copying that include a component system having at least a selenium drum for imprinting an image to be copied on a supply of copy paper. Such xerographic copy machines are an ever present piece of equipment in virtually every office in this country. The machines are manufactured and/or marketed by a number of different companies under numerous trademarks including Ricoh, Xerox, Savin, Cannon, and many others. Some of these xerographic copying devices provide a continuous photocopying capability which allows an elongated original to be continuously copied. These types of continuous copiers in general, for example, can be seen in U.S. Pat. No. 4,191,467 and U.S. Pat. No. 4,264,200. These referenced patents however are "one way" systems in which the paper path is generally elongated and straight, i.e., the copy paper supply enters one side panel of the machine and exits a copy paper outlet on the opposite side panel of the machine. The paper path between the inlet and outlet is generally a straight linear path. Generally a straight path or linear path design presents little or no problem with maintaining proper tension on the supply paper as it traverses the machine. "Straight through" paper path designs such as the following listed patents require an excessive amount of floor space and cannot be placed in restricted spaces, small areas and in corners of a room.
One particular prior art type continuous copying machine is marketed by Ricoh of America under the trademark and model number "Ricoh 420." That particular machine cannot continuously copy very long documents but rather copies a document of up to, for example, five feet (5') in length. The Ricoh 420 device does in fact have a paper inlet and a paper outlet on the same side of the machine, so that it is compact and can be placed in a corner of a room and in very small places. The operator of course can visually inspect supply paper inlet and outlet portions of the machine from one side, watching both the supply paper being fed into the machine from a lower elevation as well as the copied portion of the web being discharged from a higher elevational outlet. This machine suffers, however, in that the paper necessarily must follow not a straight but a curved, generally semicircular paper path. In attempting to follow a curved paper path, the copy paper has a tendency to become slack. This "slackness" can trigger jam switches that shut off the photocopying process. The jamming problem is aggravated when extremely long documents need to be copied such as, for example, oilfield well logging reports which may be, for example, forty to fifty feet (40'-50") in length.
Various xerographic machines and associated paper feed mechanisms have been patented which have attempted to solve the problem of continuous photocopying, or the feeding of an elongated original document for the purpose of copying. Several of these prior patented copy machines relate to the conveyance of folded computer printout paper, for example. Other patented devices as discussed below relate to the continuous feed of an elongated, continuous supply paper.
U.S. Pat. No. 3,800,922 entitled "Apparatus for Feeding Elongated Document to Electro-Photographic Copier" issued to Seiichi Yamagishi of Tokyo, Japan shows an apparatus comprising a document guide portion for receiving the document face up while permitting the operator to read the document therethrough, first drive means for forcibly driving the document received therein, a document reversing guide formed with a document passage by which the document driven by the drive means is turned face down at one end of the document table, second drive means disposed at the outlet of the document passage and including driven rollers rollingly engageable with the document under the torque thereof due to gravity to drive the document onto a document table glass at a higher circumferential speed than the first drive means, third drive means rollingly engageable with the document under gravity and to be driven at a higher circumferential speed than the second drive means, and fourth drive means disposed at the terminal end of the document table glass and including driven rollers rollingly engageable with the document under gravity, the fourth drive means being drivable at a higher circumferential speed than the third drive means only in the normal direction and idly rotatable in the reverse direction. This patent is a tractor drive unit for originals.
U.S. Pat. No. 3,997,093 issued to Aizawa et al. on Dec. 14, 1976 shows a web feed apparatus which is removably mounted on a copying machine, for feeding a web, such as an output medium of a computer, as it is paid out of a web supply tray. The apparatus comprises pin chains for driving the web, a roller for reversing the direction of movement of the web driven by the pin chains, a conveyor pivotally movable between a horizontal position and a vertical position, an operating device for operating the pin chains, a discharged web receiving tray disposed beneath the web supply tray, and a window for taking readings on the scale attached to the copying machine and indicating the sizes of copy sheets. This device pertains to the feeding of an original.
A "Sprocket Drive and Stripper Arrangement for Computer Form Feeder Apparatus" is seen in U.S. Pat. No. 4,010,882 which issued to Carl L. Turner in March of 1977. The sprocket drive device for a computer form feeder for transporting a computer printout web has a predeterminedly spaced apertures along the edges thereof along the upper and lower surfaces and about a free end of a copyboard overlying the copy platen of a copying machine, including a pin chain assembly mounted on spaced driven sprocket and idler wheels. The pin chain assembly includes a plurality of predeterminedly spaced pins extending therefrom for receipt in the spaced apertures of the web.
U.S. Pat. No. 4,079,876 entitled "Computer Forms Feeder" shows a document feeder capable of handling continuous length document materials such as computer fanfold, the feeder having spaced belts with angled projections thereon adapted to engage perforations in the document material to cause the document material to ride up on the projections during a feed cycle to lift the document material from the copy platen of the machine and prevent scrubbing of the document thereon. This is an original feed unit.
A dual purpose removable cassette for a reproducing apparatus is provided in U.S. Pat. No. 4,086,007, as well as a reproducing apparatus employing the cassette. The cassette is adapted to support both a supply of copy sheet material in the form of a fanfold web as well as an extra long document which may be in either a coiled form or a fanfold form. This is a "straight through" paper path and the paper is being pulled through the machine.
U.S. Pat. No. 4,087,172 issued to Van Dongen in May of 1978 shows a xerographic copying apparatus adapted for copying either individual or fanfold originals. For the latter, a removable fanfold handler and feeder is provided with controls to permit positioning and advance of the fanfold sheets to be correlated with the copying apparatus operation. This device has to do with original feed.
U.S. Pat. No. 4,185,760 which issued in January of 1980 shows an apparatus for concurrently feeding elongated documents and substantially correspondingly sized copy paper to a reproducing apparatus which includes a collapsible, vertically extending A-frame having a pair of opposed, divergent sides each of inverted U-shape, and pivotally interconnected at the tops thereof. One of the sides of the A-frame journals a horizontal paper roll-supporting element, and the other side of the frame carries a horizontal paper guide bar. This device is a "straight through" paper path and the paper is being pulled through the machine.
U.S. Pat. No. 4,191,457 entitled "Dual Mode Catch Tray" issued to Richard Schieck in March of 1980, and shows a dual purpose document and copy sheet receptacle for reproducing apparatus pivotally mounted at the copy output end of the apparatus and capable of acting as a copy catch tray in a first position or mode of operation and when pivotted to second position as a document catch tray in a second mode of operation. This device has to do with the receiving of a copied document or original.
U.S. Pat. No. 4,264,200 issued to Donald Tickner on Apr. 28, 1981, shows an automatic electrostatographic duplicating machine in which computer fanfold documents are fed by an automatic handling means from a supply position above the machine platen to a second position overlaying the platen below the supply position by a tractor means having motor driven sprocket means operative to advance the document material, and control means for supplying control signals to said motor driven means to advance the document material continuously, intermittently, or to selected position. This device pertains to the feeding of an original.